Torsion-elastic shaft coupling

Abstract

A shaft coupling has an input element adapted to be rotationally driven about an axis, an output element rotatable about the axis adjacent and limitedly relative to the input element, and an intermediate element rotatable about the axis adjacent and limitedly relative to both the input element and the output element. A first coupling assembly with progressive resistance to torque is fixed between one of the input and output elements and the intermediate element. A second coupling assembly with linear resistance to torque is fixed between the other of the input and output elements and the intermediate element such that torque is transmitted between the input and output elements through the coupling elements in series with each other in a single stage.

1. A shaft coupling comprising
 an input element adapted to be rotationally driven about an axis; 
 an output element rotatable about the axis adjacent and limitedly relative to the input element; 
 an intermediate element rotatable about the axis adjacent and limitedly relative to both the input element and the output element; 
 a first coupling assembly with progressive resistance to torque fixed between one of the input and output elements and the intermediate element; and 
 a second coupling assembly with linear resistance to torque fixed between the other of the input and output elements and the intermediate element such that the full torque transmitted between the input and output elements passes through each of the coupling assemblies in series with each other. 
 
     
     
       2. The shaft coupling defined in  claim 1  wherein the first coupling assembly includes a plurality of rollers. 
     
     
       3. The shaft coupling defined in  claim 1  wherein the second coupling assembly includes a pair of relatively rotatable and axially spaced parts and an elastomeric body joined to and between the parts. 
     
     
       4. The shaft coupling defined in  claim 1  wherein one of the coupling assemblies is surrounded radially by the other of the coupling assemblies. 
     
     
       5. The shaft coupling defined in  claim 4  wherein the first coupling assembly includes:
 a disk forming the one of the input and output elements and formed with an array of angularly spaced and radially outwardly open cavities; 
 a ring forming the intermediate element and formed with an array of angularly spaced and radially inwardly open cavities each radially confronting and forming a space with a respective one of the cavities of the disk; and 
 respective elastomeric rollers in the spaces. 
 
     
     
       6. The shaft coupling defined in  claim 5  wherein the cavities of one of the arrays have relative to a predetermined rotation direction about the axis a steep leading flank and a shallow trailing flank, whereby the respective rollers are compressed radially as they shift angularly in the cavities from the respective steep flank toward the respective shallow flank. 
     
     
       7. The shaft coupling defined in  claim 5  wherein the cavities of one of the arrays have relative to a predetermined rotation direction about the axis a shallow leading flank and a steep trailing flank, whereby the respective rollers are compressed radially as they shift angularly in the cavities from the respective steep flank toward the respective shallow flank. 
     
     
       8. A shaft coupling comprising
 an input element adapted to be rotationally driven about an axis; 
 an output element rotatable about the axis adjacent and limitedly relative to the input element; 
 an intermediate element rotatable about the axis adjacent and limitedly relative to both the input element and the output element; 
 a first coupling assembly with progressive resistance to torque fixed between one of the input and output elements and the intermediate element; and 
 a second coupling assembly with linear resistance to torque fixed between the other of the input and output elements and the intermediate element such that torque is transmitted between the input and output elements through the coupling elements in series with each other, the second coupling assembly including a pair of relatively rotatable and radially spaced parts and an elastomeric body joined to and between the parts. 
 
     
     
       9. A shaft coupling comprising
 an input element adapted to be rotationally driven about an axis; 
 an output element rotatable about the axis adjacent and limitedly relative to the input element; 
 an intermediate element rotatable about the axis adjacent and limitedly relative to both the input element and the output element; 
 a first coupling assembly with progressive resistance to torque fixed between one of the input and output elements and the intermediate element; and 
 a second coupling assembly with linear resistance to torque fixed between the other of the input and output elements and the intermediate element such that torque is transmitted between the input and output elements through the coupling elements in series with each other, the other of the input and output elements having an axially directed annular face and the intermediate element having an axially directed annular face confronting the face of the other of the input and output elements, the second coupling assembly comprising an elastomeric body joined to and between both of the faces. 
 
     
     
       10. A shaft coupling comprising
 an input element adapted to be rotationally driven about an axis; 
 an output element rotatable about the axis adjacent and limitedly relative to the input element; 
 an intermediate element rotatable about the axis adjacent and limitedly relative to both the input element and the output element; 
 a first coupling assembly with progressive resistance to torque fixed between one of the input and output elements and the intermediate element; and 
 a second coupling assembly with linear resistance to torque fixed between the other of the input and output elements and the intermediate element such that torque is transmitted between the input and output elements through the coupling elements in series with each other, the other of the input and output elements has a radially inwardly directed annular face and the intermediate element has a radially outwardly directed annular face confronting the face of the other of the input and output elements, the second coupling assembly comprising an elastomeric body joined to and between both of the faces.